Getting a barrel of oil out of the ground takes energy. Years ago, you could get 100 barrels of oil out of the ground with just one barrel of oil spent. Now, it's more like 20 to one, or even five to one. That compares favorably with renewable energy sources -- but it all depends on how things are counted.

Getting a barrel of oil out of the ground takes energy. Years ago, you could get 100 barrels of oil out of the ground with just one barrel of oil spent. Now, it's more like 20 to one, or even five to one. That compares favorably with renewable energy sources -- but it all depends on how things are counted.